/* Copyright 2011 Eeli Reilin. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ''AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL EELI REILIN OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation
 * are those of the authors and should not be interpreted as representing
 * official policies, either expressed or implied, of Eeli Reilin.
 */

/**
 * \file json.h
 */

#ifndef JSON_H
#define JSON_H

#include <QVariant>
#include <QString>

namespace QtJson
{

/**
 * \enum JsonToken
 */
enum JsonToken
{
    JsonTokenNone = 0,
    JsonTokenCurlyOpen = 1,
    JsonTokenCurlyClose = 2,
    JsonTokenSquaredOpen = 3,
    JsonTokenSquaredClose = 4,
    JsonTokenColon = 5,
    JsonTokenComma = 6,
    JsonTokenString = 7,
    JsonTokenNumber = 8,
    JsonTokenTrue = 9,
    JsonTokenFalse = 10,
    JsonTokenNull = 11
};

/**
 * \class Json
 * \brief A JSON data parser
 *
 * Json parses a JSON data into a QVariant hierarchy.
 */
class Json
{
public:
    /**
     * Parse a JSON string
     *
     * \param json The JSON data
     */
    static QVariant parse(const QString &json);

    /**
     * Parse a JSON string
     *
     * \param json The JSON data
     * \param success The success of the parsing
     */
    static QVariant parse(const QString &json, bool &success);

    /**
    * This method generates a textual JSON representation
    *
    * \param data The JSON data generated by the parser.
    */
    static QByteArray serialize(const QVariant &data);

    /**
    * This method generates a textual JSON representation
    *
    * \param data The JSON data generated by the parser.
    * \param indentation The current indentation (spaces) of the serialization.
    *
    * \return QByteArray Textual JSON representation
    */
    static QByteArray serialize(const QVariant &data, const QString &indentation);

private:
    /**
     * Parses a value starting from index
     *
     * \param json The JSON data
     * \param index The start index
     * \param success The success of the parse process
     *
     * \return QVariant The parsed value
     */
    static QVariant parseValue(const QString &json, int &index,
                                                       bool &success);

    /**
     * Parses an object starting from index
     *
     * \param json The JSON data
     * \param index The start index
     * \param success The success of the object parse
     *
     * \return QVariant The parsed object map
     */
    static QVariant parseObject(const QString &json, int &index,
                                                               bool &success);

    /**
     * Parses an array starting from index
     *
     * \param json The JSON data
     * \param index The starting index
     * \param success The success of the array parse
     *
     * \return QVariant The parsed variant array
     */
    static QVariant parseArray(const QString &json, int &index,
                                                               bool &success);

    /**
     * Parses a string starting from index
     *
     * \param json The JSON data
     * \param index The starting index
     * \param success The success of the string parse
     *
     * \return QVariant The parsed string
     */
    static QVariant parseString(const QString &json, int &index,
                                                            bool &success);

    /**
     * Parses a number starting from index
     *
     * \param json The JSON data
     * \param index The starting index
     *
     * \return QVariant The parsed number
     */
    static QVariant parseNumber(const QString &json, int &index);

    /**
     * Get the last index of a number starting from index
     *
     * \param json The JSON data
     * \param index The starting index
     *
     * \return The last index of the number
     */
    static int lastIndexOfNumber(const QString &json, int index);

    /**
     * Skip unwanted whitespace symbols starting from index
     *
     * \param json The JSON data
     * \param index The start index
     */
    static void eatWhitespace(const QString &json, int &index);

    /**
     * Check what token lies ahead
     *
     * \param json The JSON data
     * \param index The starting index
     *
     * \return int The upcoming token
     */
    static int lookAhead(const QString &json, int index);

    /**
     * Get the next JSON token
     *
     * \param json The JSON data
     * \param index The starting index
     *
     * \return int The next JSON token
     */
    static int nextToken(const QString &json, int &index);
};


} //end namespace

#endif //JSON_H
